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l l T.J.HUBBBLL.

SIEVE l0R SCREEN FOR GRAIN SEPAEATORS. .491.

Patented Deo; 5 188,2.

Fig. 5.

N, PETERS Pholo-Lnhagnplmr. wn'hingmn. DA c.

UNITED STATES PATENT EEICE.

THOMAS J. HUBBELL, OFR'EDWOOD CITY, CALIFORNIA.

SIEVE ORSCREEN FOR GRAIN-SEPARATORS.

SPECIFICATION forming part of Letters Patent No. 268,491, dated December 5, 1882.

f Application fuea May 1, rss2. (No model.)

To all whom it 'may concern:

Be it known that I, THOMAS J. HUBBELL, residing in Redwood City, county of San Mateo and State of California, have invented certain new and useful Improvements in Sieves or Screens for Grain-Separators; and I do hereby declare that the following is a full, c1ear,\and exact description of the same, reference being had to the accompanying drawings, in which- Figure l is a perspective view; Fig. 2, a longitudinal section, and Fig. 3 an end view.

My invention relates to an improved construction of sieve for shoes of thrashing-machines and other grain separating and clean* ing devices; and the objects of my improve- `ments are, first, to give greater amount and more effective character of wind-surface and obtain at the same time requisite strength and durability in the screen without increasing its size; and, secondly, to produce improved and more certain action of the air-blast upon the matter or particles in their passage over the screen-surface.

The following` description fully explains the nature of my invention and the manner of using it.

The screen A is formed of corrugated sheet metal, having the required apertures produced by stamping or cutting openings at suitable distance apart over the surface before the crimps or corrugations are made. To produce a screen of given size, several sections of corrugated perforated sheet metal are employed, and they are secured together, one behind the other, in a succession of steps, so that the sur-` face of one section is a little above the level of the section immediately succeeding it. The surface of the screen thus consists of a series of steps dropping in regular manner from the highest or receiving end to the-lowest or discharging end of the screen. These sections extend breadthwise from one side of the screen to the other, and their surfaces are held horizontally when the screen is in working position. At the line Wherethe back edge of one step meets with the front edge of the next one, a cross-strip, B, is interposed between them, and these two edges, overlapping somewhat, are secured to this strip at several points along its` length-one to the top face of this strip andthe other to its under face. Around the edges of the several sections thus arranged and connected a rim or frame, C, is carried `and secured, to which the ends of the cross- `strips B are fastened.

1of ridges and hollows are broken and the holv lows in one section curvein line with and are opposed to the ridges of the section next to it.

Such corrugated surface does not require the perforations to be made very close together in `the dat metal, because the operation of crimp- .ing the perforated plate gives increased amount fof apertures in a given area of surface. lrequired degree of screening-surfaceis thus obtained without reducing the strength of the The metal. Thecorrugatcd form likewise stiffens and increases the durability of the screen, so

that anV extra weight of sheet metal is not required.

The arrangement of the surface in successive steps is designed to obtain more effective application and action of the air-blast and a more rapid operation ofthe screen. apertures formed along the line of the crossstrips B by the corrugated edges of this metal gives a full outlet for the blast from below the screen and applies it outwardly in a horizontal direction over the surface of each section, in addition to the usual outlet and action upward through the screen against the matter carried on its surface. This twofold action is to facilitate the cleaning and to increase the operation of the screen. The chaff and lighterI stuff are raised and floated above the surface by one portion of the windblast,wl1ile the grain that is supported upon the screening -surface is caused to pass and progress from one level to the others in succession by the action of the other portion of the blast. `To divide and properly direct the wind in this manner,`Iplace at the line of division and rise between each section an inclined deliecting-plate, D, the upper edge of which is secured to and along or springs from the front edge of the separating cross-strips B, so that the plate is supported at an inclination, and, while extending across The series of ICO and stands at an angle with the strip B and with the screen-surface. Asimple form of con.- structin g and applying these plates is to make them in one piece with the cross-strips B, the flat portion being interposed between and receiving the edges of the sections, and the remaining width of the strip employed being then bent down to stand at an angle and eX- tend under the bottom of the corrugated section for the required distance. Thelower edge ofsuch piate,catehing the Wind, acts to split or divide it into two currents at the edge of each section, one portion being deflected upward and the other directed outward at the edge of the section across the upper surface and lon gitudinally over it in thesame direction with the lines of corrugations.

This construction of sieve or screen has many points of advantage over ordinary screens of dat surfaces. lt is less liable to choke by reason of the large area of apertures in a given surface, and it is more rapid,certain,and complete in its operation, by reason ofthe peculiar arrangement of the surface in sections and the` application of the air-blast at and through the line of division between the edges of the sections. It is readily applied and used in shoes of thrashing-machines in combination with the vibrating mechanism employed to operate the shoe, and the air-blast can be produced from the usual fan or any suitable means. f

The sections can be of any suitable width, according to the length of sieve to be made and the number of sections required, as I do not confine myinvention to any particular number or size of corrugated sections. By increasing the number of sections, however, the lines of transverse outlets afforded at the junction of one section with another, through which the air-current is directed longitudinally over the top of the section, are increased in like proportion; and it may be of advantage in some cases of use to increase the number ot' sections at the rear portion of the screen-surface Wherev the chaff and lighter stuff are in excess.

In constructing the screen of a corrugated surface I do not confine myself to the use of perforated sheet metal alone, as such surface can he formed of sections or lengt-hs of Wood Worked or bent into the required corrugated shape. from perforated sheet-plate; however, for the reason that such material is light, cheap, and easily Worked and handled.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. A sieve or screen for grain-separators, having a corrugated perforated surface composed of sections placed at dilferent levels, su bstantially as set forth.

2. A sieve or screen for grain-separators, having a corrugated perforated vsurface composed of sections placed at different levels eX- tending across the frame, and the corrugations in one section breaking line With those in the adjacent section.

3. A sieve or screen for grain-separators, having a corrugated perforated surface composed ot' sections placed at different levels, and the interposed cross-strips B, combined therewith.

4. In combination with the series of corrugated perforated sections placed in successive order, the cross-strips B and inclined deflectors D.

Witness my hand and seal.

THOMAS J. HUBBELL.

I have described them as being formed y 

